<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
  var findFinalValue = function(nums, original) {
    for (let i = 0; i < nums.length; i++) {
        if (nums[i] === original) {
            original = original * 2
            return findFinalValue(nums, original)
        }
    }
    return original
  };
  console.log(findFinalValue([5,3,6,1,12],3));
  </script>
</body>
</html>